This invention relates to a tape cassette within which there is accommodated a tape body such as magnetic tape serving as recording medium for information signals or cleaning tape for cleaning head, and so forth, of a recording/reproducing apparatus.
Hitherto, there have been widely used tape cassettes within which there is a accommodated magnetic tape as a recording medium for video signals or information signals such as data, and so forth, processed by an information processing apparatus such as computer, and the like.
In magnetic tapes accommodated within the tape cassette, when other information signals are overwritten onto the area where information signals are recorded, information signals previously recorded are erased. As a result, information signals to be preserved are erroneously erased. In view of the above, in order to prevent such overwrite recording or erroneous erasing of information signals, there is provided a write protect mechanism at tape cassette that permits recording/reproduction of information signals.
As a write protect mechanism provided at the tape cassette, there is known a mechanism composed of a discrimination hole provided at the cassette body within which the magnetic tape accommodated, and an erroneous recording prevention member for opening and closing the above-mentioned discrimination hole. When the discrimination hole is opened, this write protect mechanism inhibits recording of information signals onto magnetic tape. On the other hand, at the recording and reproducing apparatus side into which the above-mentioned tape cassette is loaded, there is provided a detection mechanism for detecting the state of the write protect mechanism. When the tape cassette is loaded with the discrimination hole opened, it is discriminated that this tape cassette inhibits write operation of information signals, thus to limit write operation of information signals.
Moreover, when the tape cassette is loaded with the discrimination hole closed, the detection mechanism at the recording and reproducing unit side discriminates that this tape cassette and permits a write operation of information signals to allow the recording and reproducing unit side to set recording mode, whereby information signals can be recorded.
Meanwhile, in tape cassettes of this kind, there have been widely used tape cassettes within which magnetic tape having a tape width of 8 mm is accommodated. As such tape cassettes, there are provided tape cassettes used as a recording medium for a recording and reproducing unit, used as an external unit of information processing unit such as computer, and so forth, and used for exclusively recording digital data handled in the information processing unit such as computer, and so forth. There are also provided tape cassettes used as a recording medium for a video tape recorder, and used for exclusively recording analog signals such as video signals or audio signals, and so forth. Tape cassettes used for recording digital data and tape cassettes used for recording video signals or audio signals are magnetic tapes having tape width of 8 mm, and are respectively accommodated within the cassette bodies of which sizes are caused to be in correspondence with each other and substantially common in external shapes. For this reason, it is very difficult to discriminate, by visual observation, between tape cassettes used for recording digital data and tape cassettes used for recording video signals or audio signals.
Meanwhile, magnetic tapes accommodated within the tape cassette used for recording data and the tape cassettes used for recording video signals or audio signals have specifications such as magnetic media, and so forth, that is different from each other. The magnetic tape accommodated within a tape cassette for recording digital data has large recording capacity as compared to the magnetic tape accommodated within a tape cassette for recording video signals or audio signals, and is required that guarantee of error rate with respect to data to be recorded is great. For this reason, in the case where the tape cassette for recording of video signals or audio signals is erroneously loaded into recording and reproducing unit of information processing apparatus so that it is used as tape cassette for recording of data signal, there are inconveniences such that recording capacity is insufficient, so that necessary data fails to be recorded or becomes missing.
Further, in the tape cassettes used for recording digital data, there are tape cassettes having different recording formats such as the width of recording track, or the pitch of recording track, and so forth, or different recording capacities. In recording and reproducing units using such tape cassette as a recording medium, there are employed recording/reproduction systems corresponding to respective recording formats.
In the tape cassettes where recording capacity is large, track width and track pitch are small in order to permit high-density recording of data. As a result, when a tape cassette having a small track width and track pitch is loaded into a recording and reproducing unit that is normally used with a tape cassette having small recording capacity for carrying out recording of data by recording format, that has a large track width and track pitch, and write operation of data is carried out, the recording track of the large capacity tape cassette that is adjacent the recording track on which data has been already recorded is scanned by magnetic head so that data recorded on this recording track is erased. As a result, data are erroneously erased.
In addition, in the case where a tape cassette having a large recording capacity is loaded into a recording and reproducing unit that exclusively uses tape cassettes having small recording capacity, and where a read operation of data is carried out, plural recording tracks adjacent to each other are scanned at the same time by the magnetic head, thus failing to carry out precise read operation of data.
An object of this invention is to provide a tape cassette that permits discrimination between tape cassettes different in specification such as recording format, and so forth, by utilizing write protect mechanism provided at the tape cassette.
Another object of this invention is to provide a tape cassette that inhibits recording of an information signal thereon when loaded into a recording and reproducing unit that is configured for cassettes of a different format, making it possible to protect the data previously-recorded on the tape cassette.
A further object of this invention is to provide a tape cassette that can provide, within a narrow region, plural write protect mechanisms functioning as discrimination means for the tape cassette.
A still further object of this invention is to provide a tape cassette that can securely change the state of the write protect mechanism while providing, within a narrow region, plural write protect mechanisms functioning as discrimination means for the tape cassette.
This invention is directed to a tape cassette in which tape body is wound across a pair of tape reels rotatably supported by the cassette body, the tape cassette including a first write protect mechanism provided in correspondence with position where there is provided a write protect mechanism provided at other tape cassette loaded with compatibility with respect to a recording/reproducing apparatus into which the tape cassette is loaded, and a second write protect mechanism provided at position that is not in correspondence with position where write protect mechanism provided at the other tape cassette is provided, wherein the first write protect mechanism is placed in write protect state at all times.
The first write protect mechanism is comprised of a discrimination hole provided at the cassette body and the second write protect mechanism comprises a discrimination hole provided at the cassette body and an erroneous recording prevention member for opening and closing the last-mentioned discrimination hole.
The erroneous recording prevention member constituting the second write protect mechanism is caused to undergo movement operation in a manner substantially perpendicular to the plane surface where discrimination hole is provided of the cassette body to open and close the discrimination hole.
A tape cassette according to this invention comprises plural first write protect mechanisms constituted by discrimination holes provided at the cassette body, and a second write protect mechanism including a discrimination hole provided at the cassette body and an erroneous recording prevention member for opening and closing the last-mentioned discrimination hole, wherein the plural discrimination holes respectively constituting the plural first write protect mechanisms and the discrimination hole constituting the second write protect mechanism are provided at the bottom surface of the cassette body in series along one side surface of the cassette body. The discrimination hole constituting the second write protect mechanism is provided between the discrimination holes constituting the first write protect mechanisms, and the erroneous recording prevention member constituting the second write protect mechanism is caused to undergo movement operation in a manner substantially perpendicular to the plane surface where the discrimination hole is provided of the cassette body.
The erroneous recording prevention member constituting the second write protect mechanism is adapted so that when it is located at the position where the discrimination hole constituting the second write protect mechanism is opened and at the position where that discrimination hole is closed, engagement portion is caused to be engaged with cassette body so that movement is limited.
At the tape cassette according to this invention, there is further provided tape discrimination mechanism for discriminating kind of tape body accommodated within the cassette body. This tape discrimination mechanism is discrimination hole provided at the cassette body.
Within the tape cassette discriminated by the tape discrimination mechanism, there is accommodated cleaning tape for cleaning head, and so forth, of the recording/reproducing unit.
Still more further objects of this invention and more practical merits or advantages obtained by this invention will become more apparent from the description of the embodiments that will be given.